The optimal bounded control of stochastic-excited systems with Duhem hysteretic components for maximizing system reliability is investigated. The Duhem hysteretic force is transformed to energy-depending damping and s...The optimal bounded control of stochastic-excited systems with Duhem hysteretic components for maximizing system reliability is investigated. The Duhem hysteretic force is transformed to energy-depending damping and stiffness by the energy dissipation balance technique. The controlled system is transformed to the equivalent non- hysteretic system. Stochastic averaging is then implemented to obtain the It5 stochastic equation associated with the total energy of the vibrating system, appropriate for eval- uating system responses. Dynamical programming equations for maximizing system re- liability are formulated by the dynamical programming principle. The optimal bounded control is derived from the maximization condition in the dynamical programming equation. Finally, the conditional reliability function and mean time of first-passage failure of the optimal Duhem systems are numerically solved from the Kolmogorov equations. The proposed procedure is illustrated with a representative example.展开更多
In the light of estimation model for ternary excess properties,an approximate analytical procedure for ternary Gibbs-Duhem equation was proposed,and verification by previous ternary systems as Cd-Bi-Pb and Zn-In-Cd wa...In the light of estimation model for ternary excess properties,an approximate analytical procedure for ternary Gibbs-Duhem equation was proposed,and verification by previous ternary systems as Cd-Bi-Pb and Zn-In-Cd was also made.展开更多
本文用函数逼近法求解了 N 元体系相平衡的 Gibbs-Duhem 方程。它的原理建立在变分法的基础上。其主要特点是将一个微分方程或偏微分方程组的两点边值问题转化为在一定精度要求下等价的求解最佳逼近函数或函数向量的非线性规划问题.它...本文用函数逼近法求解了 N 元体系相平衡的 Gibbs-Duhem 方程。它的原理建立在变分法的基础上。其主要特点是将一个微分方程或偏微分方程组的两点边值问题转化为在一定精度要求下等价的求解最佳逼近函数或函数向量的非线性规划问题.它的优点在于它对任意维的问题都具有统一的计算结构和它只需满足本质边界条件(如 y(0)=0,y(1)=1)。本文简述了该算法的基本原理,并给出实际算例,包括二元体系和三元体系汽相组成的推算,计算结果与平行算法的结果符合良好。展开更多
This paper regards the activity coefficient of salt in mixed solvents with const ant composition as a function of vapor-liquid equilibrium data by means of terna ry Gibbs-Duhem equation. A verification method includin...This paper regards the activity coefficient of salt in mixed solvents with const ant composition as a function of vapor-liquid equilibrium data by means of terna ry Gibbs-Duhem equation. A verification method including two independent criteri a for vapor-liquid equilibrium data of salt-containing system is proposed on the bases of thermodynamics and the Debye-Hückel electrolytical solution theory.A ccording to the criteria every experimental point can be verified by the calcula tion of its vapor-liquid equilibrium data.Not only is this method rigorous in th e theory,but also very convenient in the application.Under the condition of fix ing the ratio between two solvents it can be used for vapor-liquid equilibrium d ata verification of various salt-containing systems,whether the systems are isot hemic or isobaric,aqueous or non-aqueous,up to saturated or non-saturated.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11202181 and11402258)the Special Fund for the Doctoral Program of Higher Education of China(No.20120101120171)
文摘The optimal bounded control of stochastic-excited systems with Duhem hysteretic components for maximizing system reliability is investigated. The Duhem hysteretic force is transformed to energy-depending damping and stiffness by the energy dissipation balance technique. The controlled system is transformed to the equivalent non- hysteretic system. Stochastic averaging is then implemented to obtain the It5 stochastic equation associated with the total energy of the vibrating system, appropriate for eval- uating system responses. Dynamical programming equations for maximizing system re- liability are formulated by the dynamical programming principle. The optimal bounded control is derived from the maximization condition in the dynamical programming equation. Finally, the conditional reliability function and mean time of first-passage failure of the optimal Duhem systems are numerically solved from the Kolmogorov equations. The proposed procedure is illustrated with a representative example.
文摘In the light of estimation model for ternary excess properties,an approximate analytical procedure for ternary Gibbs-Duhem equation was proposed,and verification by previous ternary systems as Cd-Bi-Pb and Zn-In-Cd was also made.
基金河南省科委自然科学基金 (No 9940 3 190 0 )河南省教委自然科学基金 (No 2 0 0 0 15 0 2 8)资助项目
文摘This paper regards the activity coefficient of salt in mixed solvents with const ant composition as a function of vapor-liquid equilibrium data by means of terna ry Gibbs-Duhem equation. A verification method including two independent criteri a for vapor-liquid equilibrium data of salt-containing system is proposed on the bases of thermodynamics and the Debye-Hückel electrolytical solution theory.A ccording to the criteria every experimental point can be verified by the calcula tion of its vapor-liquid equilibrium data.Not only is this method rigorous in th e theory,but also very convenient in the application.Under the condition of fix ing the ratio between two solvents it can be used for vapor-liquid equilibrium d ata verification of various salt-containing systems,whether the systems are isot hemic or isobaric,aqueous or non-aqueous,up to saturated or non-saturated.
